This adds the required bits to wayland surfaces and ties them up
to the compositor parts.
It is based on and very similar in nature to buffer transforms.
From the specification:
> The global interface exposing surface cropping and scaling
> capabilities is used to instantiate an interface extension for a
> wl_surface object. This extended interface will then allow cropping
> and scaling the surface contents, effectively disconnecting the
> direct relationship between the buffer and the surface size.
GNOME/mutter!323

This implements the viewporter protocol which offers a cropping and scaling
capabilities to wayland clients.
There are several use cases for this, for example video players and games,
both as a convenience function and as potential performance optimization when
paired with hardware overlays etc.
GNOME/mutter!323

Until meson 0.50, setting the install parameter in 'configure_file' is ignored
if 'install_dir' is set. Then until mutter doesn't depend on such meson version
cogl_installed_tests_libexecdir should be empty unless have_installed_tests is
false, or this file will be installed anyway.
See https://github.com/mesonbuild/meson/issues/4160

For various error and warning messages, mutter includes a description of
the window, and that description includes a snippet of the title of the
window. Those snippets find their way into system logs, which then means
they can potentially find their way into bug reports and similar. Remove
the window title information to eliminate this potential privacy issue.

Unfortunately, many parts of GNOME Shell and Mutter and Clutter
still use the implicit Cogl1 API. As such, it as a transition
between the old and new APIs, it is important to keep the
implicit draw framebuffer updated.
ClutterRootNode does not keep it updated though, and it might
lead to problems when rendering offscreen textures.
Fix that by pushing and popping the root node framebuffer on
pre- and post-draw, respectively.
GNOME/mutter!405

The ClutterRootNode paint node is theoretically the
top-most node of a paint nodes tree, except that we
are not in the point of having full rendering trees
in Clutter (all rendering performed by paint nodes
is still local and immediate).
When controlling the rendering tree, MetaShapedTexture
may need to paint into an offscreen framebuffer under
some circumstations.
Expose ClutterRootNode so that MetaShapedTexture can
use it to render to offscreen framebuffers.
GNOME/mutter!405

When painting to an offscreen framebuffer, MetaShapedTexture will
need to have full control of the painting routines of paint nodes.
As such, expose clutter_paint_node_paint() to allow forcing a
paint nodes paint from MetaShapedTexture.
GNOME/mutter!405

The multitexture API is not a shortcut for multiple calls
to the single texture API. It is meant to wrap calls to
cogl_framebuffer_draw_multitexture_rectangle(), which
uses the passed texture coordinates at different layers of
the pipeline.
GNOME/mutter!405

ClutterImage is a ClutterContent implementation that
has an internally managed CoglTexture. This texture
is recreated when new image data is set.
ClutterContent implementations may have control over
the allocation of the widgets they're attached to,
through CLUTTER_REQUEST_CONTENT_SIZE. On those cases,
if the new image data differs in size from the previous
data, it is important to notify those actors about the
size change. However, currently ClutterImage does not
notify them.
With the introduction of clutter_content_invalidate_size(),
it is possible to report the size changes to attached
actors.
Adapt ClutterImage to invalidate_size() when image data
has different sizes.
GNOME/mutter!405

ClutterContent has the ability to dictate the layout of any
given actor, through the CLUTTER_REQUEST_CONTENT_SIZE request
mode.
However, there is no way for ClutterContent implementations
to notify their attached actors that the content size changed.
Add a new optional ClutterContent.invalidate_size() vfunc and
clutter_content_invalidate_size().
GNOME/mutter!405

The helper function from gdbus-codegen broadcasts the signal emission,
but we really only care about sending it to the specific peer that
created the session. Thus, only emit the signal to the particular peer
that owns the session.
https://bugzilla.gnome.org/show_bug.cgi?id=784199

If the extension is missing, the GPU copy path would not work. The code sets
the error, but forgets to return a failure. Fix this.
While adding the necessary return FALSE, also destroy the EGL context we just
created. Code refactoring shares the destroying code.
Found by reading code.
GNOME/mutter!416

If the GPU copy path would use a software renderer, fall back to the CPU
copy path. The CPU copy path is possibly faster and avoids screen
corruption issues that were observed on an Intel Haswell desktop. The
corruption was likely due to texturing from an unfinished rendering or
memory caching issues.
GNOME/mutter!325

Print the pixel format chosen for an output on a secondary GPU for
debugging. Knowing the format can aid in debugging e.g. red/blue channel
swaps and CPU copy performance issues.
This adds a DRM format printing helper in meta-crtc-kms.h. This header
is included in most native backend files making it widely available,
while DRM formats are specific to the native backend. It could be shared
with Wayland bits, DRM format codes are used there too.
The helper makes the pixel format much more readable than a "%x".
GNOME/mutter!341

When setting up an output on a secondary GPU with the CPU copy mode,
allocate the dumb buffers with a DRM format that is advertised supported
instead of hardcoding a format.
Particularly, DisplayLink devices do not quite yet support the hardcoded
DRM_FORMAT_XBGR8888. The proprietary driver stack actually ignores the
format assuming it is DRM_FORMAT_XRGB8888 which results the display
having red and blue channels swapped. This patch fixes the color swap
right now, while taking advantage if the driver adds support for XBGR
later.
The preferred_formats ordering is somewhat arbitrary. Here it is written
from glReadPixels point of view, based on my benchmarks on Intel Haswell
Desktop machine. This ordering prefers the format that was hardcoded
before.
GNOME/mutter!341

These functions allow inspecting which pixel formats a CRTC's primary
plane supports. Future patches will inspect the supported formats and
pick a framebuffer format accordingly instead of hardcoding a format.
The copy list function will be used to initialize a formats list, and
the supports format function will be used to intersect that list against
another CRTC's supported formats.
GNOME/mutter!341

This avoids having to hardcode the same fallbacks elsewhere multiple
times when determining what formats might be suitable for a set of
CRTCs. The formats_modifiers hash table is now guaranteed to be
populated with at least something, so future code will not need to
handle it being empty.
The hardcoded fallback formats are a minimal set probably supported by
most hardware. XRGB8888 is the format that, according to ancient lore,
all DRM devices should support, especially if they don't have the
capability to advertise otherwise. Mutter also hardcodes XRGB8888 as the
GBM surface format, so it is already required on primary GPUs.
XBGR8888 matches the most common OpenGL format, sans alpha channel since
scanout hardware has not traditionally supported alpha. XBGR8888 is here
also because Mutter hardcodes that format for secondary GPU outputs when
using the CPU copy path.
GNOME/mutter!341

If the IN_FORMATS property is not found, copy the formats from the DRM
plane instead. This is the fallback for getting a list of formats the
primary plane supports when DRM universal planes capability is enabled.
GNOME/mutter!341